Small changes of vascular morphology or function are indicative of early stages of cardiovascular disease leading to coronary heart disease and stroke. Development of computerized methods for quantitative non-invasive assessment of the endothelial function, intima-media thickness, and compliance is important for early assessment of cardiovascular disease. During Phase I, we developed and validated a computerized method for diameter measurement in brachial ultrasound image sequences and demonstrated its feasibility for accurate quantitation of endothelial function. This Phase II proposal expands on the work done in Phase I to develop a comprehensive tool for early detection of atherosclerosis. The specific aims of Phase II are to: 1. Develop algorithms and methods for practical, accurate, and highly automated assessment of vascular flow-mediated vasodilation, intima-media thickness, and compliance. 2. Develop a Vascular Ultrasound Analysis Workstation that will allow user-friendly assessment of vascular dimensions and function. 3. Evaluate the accuracy and reproducibility of the workstation in standardized image data. This will allow employment in large population, pharmaceutical, and clinical studies. The developed tool will have the potential to identify subjects who are destined for atherosclerotic occlusive vascular disease. The final product will be available as a software package or an integrated turn-key computer station. PROPOSED COMMERCIAL APPLICATIONS: We expect that results of our Phase II research work will be commercialized in a similar fashion as the Phase I outcome. A commercialized Phase II software package will find its application among cardiovascular researchers for epidemiologic studies, cardiovascular researchers and pharmaceutical industry for drug-related trials, and clinicians for routine assessment of stroke risk via measurement of intima-media thickness. We also envision that developed software will be adopted by ultrasound manufacturers and become integral part of vascular ultrasound machines.